Desmet Ballestra’s SULPHUREX film sulphonation technology presents outstanding advantages over the competing processes, namely:
- Excellent performances in terms of product quality, especially when sensible raw materials are processed
- Exceptionally good conversion rate and colour with maximum achievable absorption of SO3 gas
- Simpler construction, which entails easier maintenance
- Lower operating pressure
- No external cooling requirements and no need of chilling water equipment
- Extra low energy consumption
Desmet Ballestra has implemented the world’s largest sulphonation plants (24.000 Kg/h as 100% active surfactant) and is constantly optimizing its process through the continuous work of its R&D Centre.
Particularly Desmet Ballestra has developed proprietary know-how and processes for surfactant upgrading downstream the sulphonation process, i.e.: Dioxane removal and Drying process for pure dry surfactant production.
Desmet Ballestra can offer standard plant design for capacities ranging from 1 to 8 ton/hr based on a single production line and customized design for larger capacities.
Listed below are the main features of the process sections of a Desmet Ballestra SULPHUREX plant
Process Air Drying
The atmospheric air is compressed up to 0,7 barg as requested by the downstream sulphonation process.
The compressed air is dried by refrigeration and condensation of the water contained in the atmospheric air and subsequent absorption on a desiccant bed.
Main features of the unit:
- Low operating pressure design (0,7 barg max)
- Process Air Dew Point lower than -70°C
- Fully automatic regeneration of absorbent medium (silicagel/Al2O3)
- Low energy consumption due to the recovery of the hot air from SO3 production unit for absorbent medium regeneration
- High reliability and efficiency
SO3 Production
Liquid sulphur is burned with the process air in a special furnace to produce a gas containing 7% by volume of SO2.
The SO2 is then converted to SO3 in a special conversion tower equipped with 4 Vanadium based catalyst beds and intercoolers to optimize kinetically and thermodynamically the reaction yield. The SO3 gas is finally cooled to 50-60°C as requested by the sulphonation process.
Main features of the unit:
- Very high reaction yield : 98,5% guaranteed and possibility to achieve higher yield with the use of a special Cesium catalyst
- High reliability, safety and long plant lifetime due to the use of air as a cooling medium, instead of water, to minimize corrosion risks
- Special design of sulphur furnace ensuring high operating reliability and easiness
- High energetic efficiency thanks to the use of hot cooling air for silicagel regeneration in the Air Drying Unit
- Very compact design of the conversion tower with internal intercoolers
- Reduced plant start-up time due to a special sulphur furnace which does not require preheating
Sulphonation Unit
The SO3 gas outcoming the SO3 production unit is filtered by a special high efficiency brink filter to eliminate any trace of carried-over oleum. Then is fed to the top of the Multitube Falling Film Sulphonation reactor (MTFR) where also the organic raw material is fed under mass flow control. The reaction of SO3 gas with the organic raw material takes place in the MTFR.
At the outlet of the reactor the gas/liquid mixture is separated in a special gas/liquid separator and in a downstream gas cyclone. The sulphonic acid is sent to a special ageing/stabilizing unit when Linear Alkylbenzene is processed, or straight to the neutralization unit when Fatty Alcohol or Ethoxylated Fatty Alcohol are processed.
Main features of the unit:
- Product quality meeting the highest international standards
- High operating flexibility thanks to the capability to process any raw material used in detergent and surfactant industry
- High reliability and operation easiness
- Automatic in-line control of sulphonation degree
- Low energy demand thanks to the low pressure drop of the MTFR
- Optimized design achieved through over 300 industrial Film Sulphonation plants implemented and operative worldwide
Main features of the Desmet Ballestra’s Mutitube Film Sulphonation reactor
- Outstanding performances in terms of product quality
- Very high heat transfer efficiency that enables an accurate control of the temperature profile in the reactor
- Low pressure drop (0,3 barg average) resulting in a reduced energy consumption of the whole sulphonation plant
- Once through design. The sulphonation reaction is accomplished within the residence time of the reactants in the reactor (less than 1 minute) without need of external recycling loop, allowing the production of low colour and low dioxane surfactants. Additionally, this enables the automatic in-line control of the sulphonation degree through the reactor
- No external cooling requirements and no need of chilling water equipment
- High flexibility with possibility of product flying change-over with minimum product contamination
- Operation easiness
- Easy scale-up of the reactor as all distribution heads and reaction tubes are identical. Scale-up is achieved simply increasing the number of reaction tubes with practically no limitations on reactor size and capacity
- High reliability and longer lifetime thanks to the use of sophisticated corrosion resistant alloys for critical parts